Interprétation paléogéographique des données palynologiques du site du Paléolithique supérieur de Mezhyrich (Ukraine)

The results of palynological study of the Upper Paleolithic Mezhyrich site in central Ukraine are presented. Four local pollen zones were identified. The results of the palynological investigations allow us to hypothesize that the plant cover during Upper Paleolithic had a mosaic structure. The pollen record shows the presence of a few tree species with the predominance of herbaceous plants. We suggest that the river valleys and other local favorable sites were natural refugia where forest elements could survive even during the Last Glacial Maximum. These favorable landscapes to the existence of prehistoric hunters may have persisted during the Last Pleniglacial.     

Étude paléontologique du genre Sabinia (Rudiste à canaux)des récifs du Campanien de Tunisie

Campanian rudist reefs of Central Tunisia are rich in pallial-canal rudists, belonging to the genus Sabinia. The Djebel Serraguia layer shows well-preserved samples allowing to make a detailed paleontologic study. A new sub species of a previously observed species from the Maastrichtian of Yugoslavia and Turkey is described. Identified for the first time on the african margins, this new taxon gives interesting data concerning systematic and evolution of the genus Sabinia, as well as the relationships between reef provinces during the Upper Senonian. The biosedimentologic role of Sabinia within tunisian reefs is pointed out.     

Figures sédimentaireset traces d'origine biologique du Trias moyen de la bordure orientale du Massif Central signification sédimentologique et paléoécologique

The sandstones with foot-prints of reptiles and saltcasts from the Middle Triassic of the eastern border of the Massif Central (France) show a striking reptilian ichnofauna. The numerous sedimentary figures and trace fossils which are described here allow to deduce the following characteristics of the depositional environment: shallow water, lower flow regime, periodical increase of salinity. The reptiles used to pass through that environment where numerous stretches of water alternated with emerged, plant overgrown areas.     

Hyostragulum simplex n. sp. (Incertae sedis) du dévonien du massif armoricain intérêt paléobiogéographique et systématique

In the western part of the “Synclinorium median armoricain (Rade de Brest), the presence of Hyostragulum simplex n. sp. in the lower part of the Troaon formation (Upper Emsian) is a supplementary element of hercynian fauna in Brittany during lower devonian time.For the new species, characterised by the lack of a septum on the base of the corallite, a fibrous microstructure, perhaps trabecular, is shown. The systematic position of the genus is discussed but ends up with a suggestion to let it remain incertae sedis..     

Les problèmes géologiques et typologiques des sites paléolithiques dans le Nord-Est du Japon

The northeastern area of Honshu is composed of six departments: Aomori, Iwate, Akita, Miyagi, Yamagata and Fukushima. The study of Paleolithic began in 1927 and has given place to the discovery of the site of Hanaizumi. Subsequently, one pushed the research below on land and the discovery of the first paleolithic site in Iwajyuku happened in 1946. Then, H. Nakagawa took back a success of survey of the geomorphological processes and the ordering of the fluviatile terraces with some layers from the volcano-sedimentary deposit of the Pleistocene in the basin of Kitakami and the one of Mabechi. Therefore, we understood that the archaeological levels of the region contain several sedimentary deposits volcano of quaternary origin from the Mounts Öu. In the basin of Kitakami, one noted the deposit of fall pyroclastic of Aiçra (AT) above the layer of the local volcanic ash from Kurosawajiri. Especially, it is one key of an important layer, the last horizon located under AT and above the tephra of Daïfudô from the local volcano, the pyroclastic stream of Towada and the involution of the layer of the volcanic ash from Kurosawajiri. More than 610 paleolithic sites has been counted in the Northeast.     

Ostracodes du bathonien moyen et supérieur des grands-causses,sud de la France. Associations et paléoenvironnements

This work describes new species of ostracodes collected in the Middle and Upper Bathonian outcrops of the Grands-Causses, Southern France: Kirtonella vignesensis n. sp., Marslatourella bathonica n. sp., Micropneumatocythere montmejeaneansis n. sp., Praeschuleridea alzonensis n. sp., and illustrates the predominating species in the assemblages: Limnocythere larzacensis, Theriosynoecum aveyronensis et Fastigatocythere juglandiformis.Ostracode assemblages are characteristic of lacustrine to polyhaline and inner marine environments, and they vary according to changes in salinity, oxygen and trophic level.     

Les ostracodes et l'évolution paléogéographiqueau quaternaire récent du site d'Ashtart (golfe de gabès,tunisie orientale)

enTwenty-seven samples have been collected in AshtartBasin (Pelagian Sea), along the core KST 100. Studies on ostracods species enables us to recognize four main associations from - 27 000 years to the Recent; the first can be linked to the Würm III regression and the other ones to the Versilian transgression.     

Faunes d'oiseaux du pléistocène de France: Systématique, évolution et adaptation,interprétation paléoclimatique

Statistical comparison between bird populations from Lower and Middle Pleistocene and present ones makes it possible to demonstrate evolutionnary shifts such as increase in size or, on the contrary, decrease in size in some lineages and to discover some species or subspecies already found in Central Europe, in layers of the same epoch. In some other lineages the observed variations seem to be regarded as possible adaptations to local geographical conditions.Moreover the study of the birds contributes richly to the reconstitution of climates and biotops. The percentage variations of «cold birds in a given site makes it possible to confirm climatic fluctuations already discovered by other methods of study.     

Études palynologiques dans le Miocène du Cap Bon (Tunisie).Essai d'établissement d'écozones et de reconstitution paléogéographique

The palynological study of 3 borings and of an outcropin the Miocene of the Cap Bon, Langhian to Messinian (?) allowed the characterisation of 5 ecozones in this region of Tunisia and the correlation of the different sites.The inventory of about 20 000 microfossils (pollens, spores, dinoflagellates, algae and chitinous microforaminiferas) makes conspicuous the evolution of the vegetation and shows the four sites are differently evolving on a palaeogeographical point of view:

• -the drill HGA1, SSE off the actual coast, indicatesan important subsidence and here the presence of a graben; the sea sedimentation in the base becomes lagoonal, then subcontinental and there is a return of the sea in the last studied level;
• -the drill CB101, on land in the middle of the CapBon, is situated in open sea, transgressive at the base, more neritic to lagoonal or brackish at the top;
• -for the drill HW1, in front of the SE coast, we seea high sea-bed poor in sedimentation;
• -the section of Oued Khazrmia translates an emerged domain near the continental shelf. So it seems there is a gradient for subsidence and for transgression from NE to SW, obliquely with the present situation.

The palaeoclimate has always a trend to ariditymore or less important in the time, it is subtropical to warm temperate; a more humid microclimate is developing in the brackish littoral regions.The palaeogeographical evolution seems to be explained by the climatic changes and/or the eustatic variations which are of a worldwide origin or caused by tectonic in the region of the Sicilian-Tunisian strait.     

Echinodermes (Homalozoa: Cornuta et Mitrata) nouveaux pour l'Ordovicien du Massif Armoricain et conséquences paléogéographiques

Two specific genera of Bohemian Llanvirn(Sarka Formation), Reticulocarpos and Lagynocystis have been recognized in Traveusot, le Pissot and Pierre Melière Formations (Llanvirn and Llandeilo of the Armorican Massif). Though three species are new (R. pissotensis, R. sp., Lagynocystis sp.) this discovery once more underlines the relationships between Bohemia and Armorican Massif during this period.     

Les plus anciennes industries paléolithiques en Russie

Early Paleolithic sites (Oldowan and Acheulian) in the European part of Russia are concentrated in the southern part of the Russian plain, in the piedmont of the Caucasus and in the North Caucasus, south from 50 N latitude. The Taman Paleolithic complex (sites of Bogatyri/Sinyaya Balka, Rodniki 1 and 2, Kermek; and localities of Tsymbal, Lisy and Peresyp), Akushin Paleolithic complex in Central Dagestan (sites of Aynikab 1, Mukhkay 1 and 2) and complex of sites in Maritime Dagestan (sites of Rubas 1, Darvagchay 1, Darvagchay-Zaliv 1 and 4) are discovered and studied. The initial human settlement of southern Russia began about 2 Ma and went through the Caucasian isthmus along the western shore of the Caspian Sea. The most ancient Homo of the first wave of settlement from the African ancestral homeland was able to reach the Caucasus and the southern part of the Russian plain by 2 Ma, as confirmed by the Liventsovka locality in the city of Rostov-on-Don. The Acheulian is represented by stratified sites of the Early Acheulian on the territory of Dagestan. At present, it can be argued that the territory of southern Russia was part of the area of initial human settlement from Africa. It is more difficult to estimate the time and ways of the initial human settlement of Northern Asia. The few sites attributed to the Lower Paleolithic are, for the most part, geologically unconnected or are questioned as to the authenticity of the artifacts. The only clearly stratified Middle Pleistocene site, Karama in the Altai, delivered a pebble tool industry. In addition, the finds of bifaces in Tuva, near the Mongolian border mark the northern limit of the distribution of the Acheulian in Asia.     

Étude paléoenvironnementale des sédiments quaternaires du Guelb er Richât (Adrar de Mauritanie) en regard des sites voisins ou associés du Paléolithique inférieur. Discussion et perspectives

After the discoveries of pre-Acheulian and Acheulian industry accumulations in the depression of the external ring of Guelb er Richât (Mauritanian Adrar) by Théodore Monod, it was proceeded to an exhaustive study of surrounding Quaternary sediments. Slopes in the south of the cliffs of Ordovician quartzite sandstones are covered with chaos of blocks where from go down torrential ravines which fed irregularly the alluvial plains of oueds Akerdil and Bamouéré. The torrential alluviums consist from two- to three-graded sequences of coarse sediments which were studied since the foot of the cliff down to alluvial fans. The datings of tests of mollusks of brackish waters and of phreatogenic calcitic cementations allowed to obtain a coherent chronostratigraphy based on 11 datings AMS of the ¹⁴C. These ages included between 15.000 and 7.730 BP correspond to the last climatic optimum or African Humid Period. Textural and mineralogical analyses of the torrential sequences allow to show a duality of origin of the materials of the accumulation partly deriving from more or less degraded Cambro-Ordovician basement (proximal source) and partly renewed by wind contributions during the long Meso-Cenozoic emersion (distal source). The palaeomagnetic measurements indicate that the great majority of the deposits accumulated during the last one normal magnetozone. Some altered deposits intermediate between the Paleozoic basement and the torrential sequences of the Late Quaternary present a negative magnetic inclination and a strong magnetic susceptibility linked to the presence of hematite grains; they are likened to more or less in situ reworked Cambrian-Ordovician tops. These conclusions leave not enough hope to identify on the slopes of Early Pleistocene sediments contemporary of the first Human populations. The strong accumulations of chopping-tools of the Akerdil Oued and of coarse hand-axes of the ravines of Cherirat indicate a credibly autochton origin of these big tools made in situ and which were concentrated by the successive wind deflations. Their mechanical dispersal was limited by their big size and by frequent calcitic cementations, such processes of fossilization were able to develop and to repeat during the ancient episodes of the Pleistocene. This hypothesis would lead us to envisage probable industry remains buried in depth into the filling of the outer alluvial plain of the Guelb er Richât.     

Comparaison entre des Crustacésa Céphalon isolé, a propos d'un beau matériel de syncarides du paléozoïque implications phylogéniques

Are the Eumalacostraca issued from a model of Crustacea which the carapace would have disapeared later on in some of them, and persisted in others, or from one without carapace that some of its decendants would have acquired? In the two instances this ancestor would goes far back, seeing that, already, in the Devonian, Syncarida, Stomatopoda, Phyllocarida and Eocarida were differenciated. With regard to the preliminary survey on a fine material of Syncarida from the Stephanian of the region of Autun, comparisons between two models of Crustaceans from which the cephalon includes only sensorial and gnathal segments, without adjunction of any thoracic metamere, allow to specify the notion of carapace, and to surround the question. The great oldness of the origin of the phyla possessing or not possessing a carapace seems to exclude the hypothesis of a passing over from one model to the other and suggests a representation of the common ancestor which have to be searched in the Cambrian period.     

Le mammouth dans l’art paléolithique

The mammoth, an emblematic animal of the Prehistory, possesses an important place in the depictions made by prehistoric artists, both in parietal art (cave art) and in mobile art. Its image is known from the Aurignacian, at the beginning of the Upper Palaeolithic, until the end of the Last Ice Age, the Magdalenian. However, its geographical and chronological distribution is dissimilar. Mammoth depictions are generally more frequent during the Aurignacian where this animal is found engraved and painted in the Chauvet cave for example and carved from ivory in several cave sites of the Swabian Jura. The Magdalenian cave of Rouffignac and its 160 representations constitute a notable exception. From a formal point of view, the representations of mammoth are elaborated in a rather constant way, like the characteristic cephalic contour and the typical back of the animal, at least as it could be seen in nature. The representations are often even limited to a cursive line with a double curvature that expresses the pachyderm. On the other hand some drawings show intimate details. Sometimes the tusks of the mammoths are not indicated, but certain stylistic features, such as the ventral arch, are relatively reliable chronological markers. Finally, one cannot ignore the ethological or seasonal expressions that sometimes link the mammoths to each other, in a row or in confrontation. This animal obviously inspired the artists of the prehistory who created various portraits of the mammoth.     

Anémie du sujet âgé

Anaemia is common in patients older than 75 years. Patho-physiologic mechanisms of anaemia are similar to that involved in younger patients even though certain mechanisms are more common in the elderly. Practical decisional algorithms have to be used for the diagnosis of anaemia. Risk factors for anaemia have been identified in this age group: institutionalization, bad socio-economic conditions, co-morbid conditions. Particular emphasis is given to several points:

1. The clinical tolerance of anaemia is the most important feature to take into account in older patients, rather than the decline of the haemoglobin level. Even if the haemoglobin level is only slightly decreased, evaluation of anaemia should be performed by the geriatrician, including, if needed, the achievement of a bone-marrow aspiration.
2. Causes of anaemia are often multiple, due to frequent comorbid conditions and acute illnesses, associated with nutritional deficiencies, inflammation… Chronic kidney disease and dysthyroidia are also common.
3. Nutritional deficiencies (iron, folate and/or B12 deficiency) are frequent and their cause has to be identified.
4. The prevalence of myelodysplastic syndromes, which are clonal diseases, is probably underestimated in this age group.